The present invention relates generally to the field of wound dressings. More specifically, the invention pertains to wound packing materials.
Over the years, the wound care industry has developed a wide variety of products designed to promote wound healing. Relatively recent developments include the introduction of polymer-based foams as absorbent material for wound dressings.
Polymer-based foams, such as urethane foams, are porous, permitting the absorption of fluids such as wound exudate, and flexible, permitting the dressings to adapt to contours of the wound and adjacent skin. Unlike conventional cloth-based absorbents, the foams are also resilient, i.e., when the foam is folded over upon itself, a permanent crease cannot be formed by hand pressure; the foam springs back into its original shape. This resiliency, however, is a hindrance to the use of such foams as wound packing materials. A sheet of resilient foam, when folded upon itself to create wound packing of a size appropriate for a particular wound, is difficult to retain in this configuration during insertion. One solution to this problem is provided in U.S. Pat. No. 4,664,662, wherein small pieces of foam are provided within a flexible, porous outer sack to form a wound packing product. This product can then be used to pack a wound by direct insertion. This product, however, cannot be readily resized or reshaped to provide an optimal fit to a particular wound.
Further problems in wound care have arisen due to the proliferation of wound dressings. For example, several dressing products stocked in medical facilities, upon visual inspection, may appear to be suitable for a particular use, but in fact may not be suitable, potentially leading to subsequent problems arising from improper treatment.
Thus, there exists a need for wound dressings that provide the advantages inherent in polymer-based foam dressings, but that also address the foregoing and other problems associated therewith.
The present invention meets the foregoing and other needs by providing, in one aspect, a wound packing material comprising a resilient polymer-based foam sheet of a predetermined thickness. The foam sheet includes at least one slit of a predetermined length extending into the foam to a predetermined depth. This slit, or slits, permits the foam, when folded upon itself, to occupy a smaller volume than the foam would occupy when folded over upon itself in the same manner in the absence of the slit. This is thought to be the result of the slit""s effect of reducing the amount of material that binds the foam together, providing for a corresponding lessening in the foam""s resistance to folding.
One benefit of the present invention is that it minimizes the amount of open space between folds, permitting a greater quantity of foam to be provided within a given volume. When inserted into a wound as a packing material, this relative increase in the quantity of foam within the wound provides for increased liquid absorption capacity over a given period of time, lengthening the time between dressing changes and enhancing wound healing. The present invention further requires less compressive force to maintain the foam sheet in a folded-over configuration, as compared to a foam sheet having the same formulation and dimensions without one or more slits. This permits a health care provider to more easily configure the foam sheet to match the dimensions of a given wound, and subsequently handle the folded packing material just prior to and during insertion into a wound. This advantage is particularly pronounced in a preferred configuration of the invention, wherein a plurality of substantially linear slits that extend through the entire thickness of the foam are provided, permitting a caregiver to readily customize the foam sheet to fit a variety of wounds.
The present invention further permits easy differentiation between dressings. For example, one viewing the slits in the packing material sheet, particularly those in the preferred embodiment that extend through the dressing, would likely not readily confuse such a packing material with a continuous foam sheet useful as a secondary wound covering, the latter being used to insure sterility of the wound.
These and other features and advantages of the various aspects of the present invention will be more readily apparent upon reading the following description of a preferred exemplified embodiment of the invention and upon reference to the accompanying drawings.